Single and Combined Effect of Fine and Coarse Tire Rubbers on the Static, Microstructural, and Impact Properties of Concrete

Abstract

This paper presents an experimental investigation on the static, microstructural and impact properties of concrete incorporating tire rubbers. Fine tire rubber (FR) and coarse tire rubber (CR) were used to replace fine and coarse aggregates, respectively, by 10 and 20% by volume. The single and combined effects of tire rubbers on the unit weight, mechanical properties (compressive strength, split tensile strength, flexural strength, and flexural toughness properties) and impact resistance of concrete were evaluated. Drop-weight test using concrete beams was conducted to evaluate the impact behavior of concrete. The microstructure of concrete was also investigated using SEM analysis. The results showed that incorporation of FR and CR reduced the unit weight, compressive strength, and flexural strength of concrete. Lower content of tire rubbers increased the split tensile strength of concrete, however higher content of tire rubbers resulted in its reduction. On the other hand, tire rubbers were found to remarkably enhance the energy absorption capacity, fracture energy and impact strength of concrete. SEM observations revealed that rubberized concretes had more porosity and weaker interfacial transition zone than normal concrete. In general, when FR and CR were used together, they showed an average static and impact performance compared to their single use.